The fries at In-N-Out are cut from whole potatoes in every restaurant and fried frequently in small batches for freshness, but have an overcooked quality that some diners will not enjoy. Larry Olmsted for USA TODAY

The scene: Few – if any – fast food chains enjoy the fandom given to California-based In-N-Out Burger, which has built an almost cult-like following since its first store opened in the Los Angeles area in 1948. The chain's iconic arrow logo was developed six years later, and relatively little has changed since - except that there are now nearly 300 locations across every part of California as well as Arizona, Nevada, Utah and, most recently, Texas.

Size and external appearance vary from store to store, except for the instantly recognizable arrow logo sign, but inside they are almost identical – with a white-tile, corner-shaped ordering counter beneath menu boards and a general '50s car-hop feel (right down to the paper hats many employees wear). Otherwise the interior resembles most other fast-food eateries, with synthetic chairs, tables and booths, but the counter itself has much more of a timeless diner feel. In most cases you can also see a huge bank of deep fryers, since a signature of the chain is very fresh and continuously made fries in small batches.

The most obvious thing that sets In-N-Out apart from its competitors is the scant menu, which ostensibly features nothing but burgers and cheeseburgers, plus fries, shakes and soft drinks. No chicken nuggets, fried fish, salads, breakfast sandwiches, onion rings and no wraps of any kind. Burgers and fries are the mainstays, though In-N-Out is also famed for its "secret menu" with many more variations on these staples (see below).

Reason to visit: Burgers with lots of toppings, especially the "secret" grilled onions

The food: Despite its very passionate loyal following, the actual burgers at In-N-Out are not especially good. The very basic, thin fast-food patties housed in generic buns are nearly identical to those at McDonald's or Burger King. What does set them apart are the trimmings, as the chain emphasizes freshness. The thick-sliced tomato, onion and crispy lettuce are noticeably superior to their competitors. A burger with the works, which includes their signature "spread" – think Thousand Island dressing – becomes a substantial and fairly tasty combo; a great value at less than two bucks for a burger (and just $3.30 for a loaded double cheeseburger). If you order your burgers or cheeseburgers more on the plain side, though, you may have trouble understanding what the In-N-Out fuss is all about.

Freshness is a big part of their fans' passion, and the chain makes it a point to emphasize that its stores have no microwaves, heat lamps or freezer. Every burger is cooked to order, one at a time. The chain has two patty facilities where it grinds its own meat using whole cuts from regular distributors, whereas many fast-food chains get their patties frozen directly from third-party meat processing plants. Likewise, potatoes are hand-cut in each store and fried in 100% vegetable oils in frequent, small batches. The shakes are made from actual ice cream.

That's the good news.

The bad news is that with the exception of the toppings, none of this freshness matters much. The patties don't taste appreciably better, and for fast food, take a long time to arrive without being worth the extra wait. The shakes still have that synthetic taste common to the big fast-food chains and are nothing special; and the fries have a distinctive taste that I do not like – a too crunchy, almost overcooked quality. It's not a matter of crispness, as I love crisp fries, it's more as if they have been cooked to the point of the liquid evaporating within and are too dry. Since they are unusual, some consumers fall on either side of the divide; I have friends who respectively love or hate the fries.

For more than half a century In-N-Out has offered preparations not found on its very simple and straightforward menu, which limits burger choices to hamburger, cheeseburger and the signature "Double Double," with two beef patties and two slices of American cheese. These extras are known to fans as the "secret menu," though In-N-Out lists some of it on their website (but not in stores) as the "not so secret menu." Most items are simply variations on the regulars, such as the 3x3 and 4x4, which take the double double and make it bigger with three or four patties and slices of cheese. There's a grilled cheese, which is basically the burger without the patty, and burgers served low-carb "protein style," which come wrapped in lettuce rather than a bun. Finally, there is "animal style," which adds extra spread, pickle and grilled onions to "mustard-grilled" patties. These are patties griddled after being topped with mustard for a distinctive cooked-in taste; while not listed on the website, you can get any burger mustard-grilled. You can also always request grilled-versus-raw onions, which is important to know because the rich and tender – almost jam-like – grilled onions are perhaps the most standout menu item. A final "secret" item of note that's not listed on the website but is readily available is the cheese fries – a normal tray of fries covered with two slices of American cheese and popped into a fast-cooking oven for a few seconds. Cheese fries are better than the regular fries, at least the top layer, which is as far as the melted cheese penetrates.

For standard-fare burgers, In-N-Out is nothing special, but they are considerably better in versions with multiple toppings and off-menu preparations. The prices are very reasonable and the service is noticeably better and friendlier than other fast-food chains. Every time you order, you are told that "you are guest number ___" for picking up your order, and you do feel more like a guest than a customer.

Larry Olmsted has been writing about food and travel for more than 15 years. An avid eater and cook, he has attended cooking classes in Italy, judged a BBQ contest and once dined with Julia Child. Follow him on Twitter, @TravelFoodGuy, and if there's a unique American eatery you think he should visit, send him an e-mail at travel@usatoday.com. Some of the venues reviewed by this column provided complimentary services.